Systems for testing the weathering and lightfastness of products such as fabric samples, painted panels, and plastics are presently available, being sold for example by the Atlas Electric Devices Company of Chicago, Ill. These devices test the weathering and lightfastness properties of materials and products under closely controlled conditions.
In the natural environment, light, heat, and moisture combine synergistically to cause optical, mechanical, and chemical changes in products which are exposed to outdoor weathering conditions. Typically, the apparatus can be used to obtain such weathering data on an accelerated time basis, to permit product manufacturers to gain information as to how their products will stand up to weathering over the months or years.
Suga, U.S. Pat. No. 4,627,287 discloses a light resistant tester for testing the lightfastness and weathering capabilities of products, where air is circulated through the system to control the temperature of samples being tested so that they are not overheated by the radiation source, which typically may be a xenon lamp. The patent is directed to a technique for air cooling the system without creating nonuniform cooling of the samples being tested.
In accordance with this invention, an improvement to weathering testing systems is provided in which samples being tested may be uniformly air cooled with greater efficiency, requiring the circulation of less air. This enables the use of a lower powered air pump which operates at a lower speed of operation, for savings of power, while lengthening the useful life of the air pump, which can thus be a lower capacity, lower cost pump. Additionally, the weathering testing system of this invention may have the sample temperature controlled in an automated manner so that the temperatures of the samples may be reliably maintained at a predetermined value without constant monitoring.